Ice making apparatus



Jan. 28, 1969 L. R. PUGH ICE MAKING APPARATUS Filed March 10, 1967 Bin Thermosfo? Cutoff Sourci United States Patent 7 Claims ABSTRACT OF THE DISCLOSURE An automatic ice making machine designed to produce ice in substantially large sheets which includes a vacuumsealed freezer plate having dual ice making surfaces and cooperative control instrumentalities as well as crushing means associated therewith.

One of the more satisfactory types of ice making machines presently in use freezes a slab or sheet of ice on a single freezing surface and, by the subsequent application of heat, releases that frozen slab and transfers it to an ice cutter or crusher associated nearby. Ice making machines of this type require relatively complex controls in order to time properly the freezing of an ice slab, the application of heat to remove the slab and the crushing of the slab once it has been removed from the freezing surface.

The freezing time required in solidifying water flowing over the freezing surface of a freezer plate depends upon the heat transfer characteristics of evaporator coil material and the metallic covering of the plate freezing surface of the plate and the distance separating these elements. Conventional sheet forming machines usually employ a single inclined surface of the freezer plate for the ice making process so that when the sheets are harvested, they will slide gravitationally downward into a cube forming or ice crushing apparatus. While machines of this type have produced most satisfactory results, devices of smaller capacity still have limitations in their ice making capabilities since heat transfer makes the freezing cycle somewhat lengthy, and the single ice freezing surface limits the ice making capacity of the machine decidedly.

Brief summary 0 the invention ice making machine of the type described which operates to freeze water applied to both surfaces of a vertically disposed freezer plate to form ice sheets which can subsequently be removed for reduction to pieces of smaller dimension.

Yet another object of the present invention is to produce a machine of the type described which operates to remove free water and snow from inclusion with the pieces of ice thus furnishing ice which is less likely to agglomerate or form into masses from which separate pieces are not easily separable.

Still another object of the present invention is to provide a vacuum-sealed freezer plate which will firmly grip the evaporator coil of the refrigerating system and accelerate and increase heat transfer from the water flowing over the freezing surface of the plate to the refrigerant passing through the evaporator coils.

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Yet still another object of the present invention is to provide a machine of the type described which is selfcleaning because of its quick freezing characteristics and Vertical plate positioning and because the make-up tank receives excess water which flows over the freezing surface and carries with it dirt, dust particles, and the like.

These and further objects of the present invention will become readily apparent to those skilled in the art upon the further consideration of the following description of specific embodiments when read in conjunction with the accompanying drawings wherein like characters of reference indicate like parts throughout the several figures.

Figure description FIG. 1 is a perspective exterior view of an ice making apparatus embodying the improvements of the present invention;

FIG. 2 is a perspective, fragmentary, isolated and schematic diagram of the refrigeration and water circulation systems embodying the present invention;

FIG. 3 is an end elevational, sectional and isolated view of the vacuum-sealed freezer plate having dual freezing surfaces and its positioning with respect to the deflector and ice crushing apparatus of the present invention; and

FIG. 4 is a block wiring diagram of the electrical apparatus and control instrumentalities employed in the present invention.

Detailed description Referring now to the drawings, an ice making machine generally designated 10 embodies conventional refrigerating components and control instrumentalities in a refrigerating system to freeze ice in selected sizes and shapes for consumer use. The commonly used model supports sliding doors 12 along an inclined front surface 14 so that the user may conveniently scoop preformed cubes or crushed particles from within an ice collecting container located inside the shell of the apparatus. The machine is operated from a conventional volt AC supply source and controlled by manually operable instrumentalities 16 including an Off-On switch 17 positioned-on the side 18 of the cabinet.

The refrigerating system employed in the preferred ice making machine embodying the present invention consists essentially of a sealed compressor 22 arranged to compress a gaseous refrigerant and deliver it through the outlet fitting 24 to a finned condenser 26 provided with a motor-driven fan or blower 28 in a manner quite conventional in the art. The condenser 26 cools and liquifies the refrigerant and passes it through a line 30 to an auxiliary heat exchanger 32 consisting of a coil (not shown) through which the refrigerant is carried for additional cooling. The heat exchanger also prevents slugging in the compressor on the defrost cycle. From the heat exchanger 32 the refrigerant is conducted into a line 34 through an expansion valve 36 and thence to the coil 38 of a suitable evaporator generally designated 40 which is encapsulated by a freezer plate generally designated 42. A refrigerant return line 44 leads from the evaporator coil 38 back to the heat exchanger 32 and thence back to the compressor 22 through line 46. The expansion valve 36 is controlled by a thermostat bulb (not shown) located on the refrigerant return line in a manner well understood in the art.

A hot gas by-pass line 48 extends from the compressor 22 through a solenoid valve 50 and then into line 34 leading to the evaporator coil 38. Thus in the normal operation of the apparatus, the gas fed through the compressor 22 will be liquified in the condenser 26, further cooled in the heat exchanger 32 and from there will flow to the expansion valve 36 where the flow of refrigerant through the valve will be thermostatically controlled to feed the required amount of refrigerant through the evaporator coil 38. This action results in freezing sheets of ice along the freezing surfaces 52 of plate 40, and when the freezing cycle has been completed, the sheets of ice formed are automatically removed by heating the surfaces 52 of the freezing plate to release the ice therefrom. This is accomplished by opening the solenoid valve 50 to permit hot gasses from the refrigerant compressor to pass through the evaporator coil 38. The sheets of ice adhering to the surfaces 52 of plate 40 are broken free in approximately 75 to 90 seconds after the operation valve 50 and the injection of hot gas into the evaporator coil 38 which momentarily converts the coil to a heater.

The machine is provided with a water connection 52 to .supply the water necessary for the production of ice. A water pump 54 urges water to dual spray pipes 56 which extend on either side of the upper edge of the freezer plate 40 and contain a number of perforations therein so that water may be uniformly applied to the surfaces 52 of plate 40.

The system embodying the present invention is also supplied with means to circulate continuously water over the freezing surfaces during the refrigerating cycle. Thus tank 58 suspended below plate 40 is initially supplied with some water by pump 54, and this water is continuously cooled and recirculated through line 60 to pump 54 and then over the surfaces of the freezing plate until the water required for making a single batch of ice sheets is completely frozen. Some of the remaining water in tank 58 (referred to as dreg water) is then automatically flushed from the tank through a stand pipe 59 and directed to the drain of the machine. By thus freezing water in a continual flowing state, the minerals, hardness and other impurities present in the supply water do not accumulate in the frozen product but become concentrated in the dreg water which accumulates at the bottom of tank 58 and empties through pipe 59 and are thus eliminated from the ice. As a result the machine will produce crystal clear ice cubes having no perceptible color or cloudiness and consisting of water of much greater purity than the water supply normally provides.

Since it is desirable that an ice making machine of the type described be completely automatic in operation, it is provided with control devices such that the water required for freezing and cooling is automatically measured and injected into the system as required, and the freezing and harvesting cycles of the mechanism are automatically alternated in proper time relation. The controls are best illustrated in FIG. 4 and are conventional for ice machines of the character described except for those particularly included components which are operative with the novel vacuum packed freezer plate having dual freezing surfaces utilized herein. These controls will be particularly described after the structural characteristics of the plate and its related elements have been set forth.

The novel freezer plate 40 embodied in the ice making equipment just described is vertically positioned (see FIG. 3) to receive a water spray 62 emitted from perforated pipes 56, and because of the vertical alignment of the plate, the evenly distributed spray moves uniformly down each surface 52. The plate is of a square or rectangular shape conveniently measuring about sixteen inches per side. The encapsulated evaporator coil 38 is totally sealed within the plate walls by an air evacuation technique creating a vacuum therein which will cause the outside atmospheric pressure to collapse the plate walls directly against coil 38. Thus the plate forms a sealed air evacuated chamber about the evaporator within which a vacuum is established of magnitude sufficient to cause the freezing surfaces of the plate to rest against the evaporator coil 38 so that heat transfer from the water flowing over the freezing surfaces through the contiguous evaporator walls and surfaces to the refrigerant of the system is accelerated and increased. A vacuum of 29 inches of mercury has proven to be completely satisfactory in the construction of the vacuum sealed plate.

By providing dual surfaces 52, each being receptive to water flowing thereacross and capable of freezing a sheet of ice thereon when the refrigerating system is in operation, it will be obvious that a decided increase in ice making capacity is achieved as the heat transfer through the adjacent materials of the plate and evaporator accelerate the freezing cycle.

A deflector generally designated 64 has been positioned beneath plate 40 and is pivota'ble about point 65 from a retracted position (see dotted outline in FIG. 3) to an engaging position and is adapted to direct water passing over the freezing surfaces 52 to the make-up tank when in the intersecting position. Similarly, the deflector will permit harvested ice to pass without interruption during the harvesting cycle so that this ice can fall free to the crushing apparatus described below. The pivotal movement (see arrow) of the deflector 64 is controlled by a solenoid operated relay, the operation of which will be particularly described subsequently.

Generally below but positioned slightly off center from the plate 40 is an ice crushing appaartus shown generally as 66 which includes a cylindrical member 68 having a number of circumferentially and laterally spaced apart rigid fingers or spikes 70 extending outwardly therefrom, member 68 being driven by a motor 71. An ice collecting container 72 is associated with the crusher to accumulate the clear crushed ice for easy removal and use.

The unique and novel components of the control instrumentalities include an ice thickness sensing thermostat 74 which is operatively connected with at least one of the two freezing surfaces 52 of the plate, the thermostat operating when the temperature of the ice surface indicates a predetermined thickness. When the thermostat 74 operates, the hot gas solenoid valve 50 is actuated so that hot gas fed directly from the compressor 22 is introduced into the evaporator coil 38 thus causing that coil to become a heater and to loosen the ice sheets formed on the surfaces 52. The injection of hot gas into coil 38 causes the harvesting operation wherein the sheets of ice are dislodged and fall free to the crushing apparatus 66 below.

The actuation of thermostat 74 also triggers the 60 second time delay relay 76 which in turn controls the deflector solenoid 78. After the harvesting operation commences, the time delay relay retains the deflector 66 in the engaging position for a period of time (60 seconds) sufficient to insure that all flowing Water along the surfaces 52 has dripped free of those surfaces and collected in the make-up tank 58. Operation of the ice thickness thermostat 74 also cuts off the water supply through pipes 56. After the relay time delay period of 60 seconds has elapsed which is still some 15 to 30 seconds before the harvesting operation, the relay 76 operates solenoid 78 so that deflector 64 is pivoted to the retracted position. When the surfaces 52 are of suflicient warmth due to the introduction of hot gases through coil 38, the sheets of ice formed thereon will then fall directly to the crusher device 66. The time delay interval provided by the relay 76 enables all moisture and sludge to pass into the make-up tank and assures that the ice particles formed when the loosened sheets fall to the crusher device 66 are moisture free and will not agglomerate or solidify in masses.

The surfaces 52 of the freezer plate may be of any suitable material but it has been found to be desirable to use tin plated copper for faster heat transfer.

The deflector is trough-shaped because of slightly uptured edges 74 insuring positive flow into the make-up tank of the water and sludge collected from the plate surfaces 52.

met of the freezing plate, the encapsulated evaporator coil, the deflector, crushing means and control instrumentalities as well as other phases of the present inventive concept in light of the above teachings without departing from the real spirit and purpose of this invention. In light of these teachings, it is clear that modifications of structural components and functional characteristics as well as the use of equivalents to the elements herein illustrated and described are reasonably included and contemplated.

What is claimed is:

1. An ice making machine having a condenser, compressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement comprising: at least one freezer plate encapsulating the evaporator, the plate having dual freezing surfaces each being receptive to water flowing thereacross and capable of freezing a sheet of ice thereon when the refrigerating system is operative; ice thickness sensing means associated with at least one of said freezing surfaces; harvesting means responsive to said sensing means to terminate the freezing operation and harvest the ice formed on the freezing surface when the formed ice reached a predetermined thickness; and a deflector adjacent said plate and movable from a retracted position to an engaging position and adapted to direct unfrozen water passing over the freezing surfaces to a remote location when in the engaging position and to allow harvested ice to pass a differing location when in the retracted position.

2. In an ice making machine having a condenser, compressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement as claimed in claim 1, said plate forming a sealed air-evacuated chamber about the evaporator within which a vacuum is established of magnitude sufficient to cause said plate freezing surfaces to rest against the evaporator so that heat transfer from water flowing over said surfaces through the contiguous evaporator walls and surfaces to the refrigerant of the system is accelerated and increased.

3. An ice making machine having a condenser, compressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement as claimed in claim 1, further comprising: means operative with said harvesting means for displacing said deflector from the engaging to the retracted position when the ice is harvested.

4. In an ice making machine having a condenser, compressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement as claimed in claim 1 further comprising: ice crushing means proximate said plate and adapted to receive the harvested sheets of ice from said plate surfaces and break the ice into smaller segments; and ice collecting means associated with said crushing means.

5. In an ice making machine having a condenser, oompressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement as claimed in claim 2 further comprising: ice crushing means proximate said plate and adapted to receive the harvested sheets of ice from said plate surfaces and break the ice into smaller segments; and ice collecting means associated with said crushing means.

6. In an ice making machine having a condenser, compressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement as claimed in claim 4, said ice crushing means including a cylindrical member having a plurality of circumferentially and laterally spaced apart rigid fingers extending outwardly therefrom.

7. In an ice making machine having a condenser, compressor, evaporator and circulating refrigerant forming a refrigerating system, the improvement as claimed in claim 5, said ice crushing means including a cylindrical member having a plurality of circumferentially and lateraly spaced apart rigid fingers extending outwardly therefrom.

References Cited UNITED STATES PATENTS 2,166,161 7/ 1939' Kleist. 2,436,389 2/ 1948 Kleist. 2,552,635 5/1951 Kleist. 2,524,815 10/1950 Leeson 62-320 2,607,203 8/1952 Kleist 62282 2,995,017 8/1961 Breeding 62-320 X 3,277,661 10/1966 Dwyer 62 348 X ROBERT A. OLEARY, Primary Examiner. WILLIAM E. WAGNER, Assistant Examiner.

\ US. 01. X.R. 62344, 347 

